Crystal structure and Hirshfeld surface analysis of 2,2′-[(3,5-di-tert-butyl-4-hydroxyphenyl)methanediyl]bis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one)

In the title compound, molecules are linked together by O—H⋯O and C—H⋯O hydrogen bonds, forming zigzag chains that are parallel to the (001) plane and run along the b-axis direction. van der Waals interactions between these chains along the a and c axes maintain the molecular packing.


Chemical context
The various carbon-carbon bond-formation techniques play important roles in organic chemistry (Celik et al., 2023;Chalkha et al., 2023;Tapera et al., 2022). Xanthene derivatives have broad applications in medicine as a result of their antiinflammatory, antibacterial, antiviral, antifungal, anti-depressant, antiplasmodial and anti-malarial activity (Maia et al., 2021). They are a special class of oxygen-incorporating tricyclic systems. The xanthene moiety is also found in various natural compounds and has a wide spectrum of therapeutic and pharmacological properties. Aside from medicinal applications, xanthene dyes have been used for diagnostic and imaging applications (Khan & Sekar, 2022;Majumdar et al., 2022;Lakhrissi et al., 2022).

Figure 2
The packing of the title compound viewed along the a-axis with O-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds shown as dashed lines.

Figure 3
A view of the zigzag chains running along the b-axis direction of the title compound with O-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds shown as dashed lines.

Figure 1
The molecular structure of the title compound, showing the atom labelling and displacement ellipsoids drawn at the 30% probability level.
To quantify the intermolecular interactions, a Hirshfeld surface analysis was performed and CrystalExplorer17 (Turner et al., 2017) was used to obtain the accompanying twodimensional fingerprint plots. Fig. 4 shows the Hirshfeld surface mapped onto d norm using a common surface resolution and a constant color scale of À0.4467 (red) to 1.6498 (blue) a.u. On the Hirshfeld surface, shorter and longer contacts are indicated by red and blue spots, respectively, and contacts with lengths about equal to the sum of the van der Waals radii are indicated by white spots. The O-HÁ Á ÁO and C-HÁ Á ÁO interactions are represented by the two most significant red spots on the d norm surface (Tables 1 and 2). Fig. 5 depicts the two-dimensional fingerprint plots of (d i , d e ) points from all the contacts contributing to the Hirshfeld surface analysis in normal mode for all atoms. The most important intermolecular interactions are HÁ Á ÁH contacts, contributing 76.8% to the overall crystal packing. Other interactions and their respective contributions are OÁ Á ÁH/HÁ Á ÁO (15.2%), CÁ Á ÁH/HÁ Á ÁC (6.9%) and OÁ Á ÁO (1.0%). The Hirshfeld surface study verifies the significance of H-atom interactions in the packing formation. The significant frequency of HÁ Á ÁH and OÁ Á ÁH/HÁ Á ÁO interactions implies that van der Waals interactions and hydrogen bonding are important in crystal packing (Hathwar et al., 2015).
In I, II, III, IV, VIII, IX and X, the two cyclohexane rings adopt an envelope conformation, while in VI and VII they exhibit a half-chair conformation. In all of these crystals, molecules are connected via O-HÁ Á ÁO hydrogen bonds. In X, there are also O-HÁ Á ÁO hydrogen bonds involving the water molecules. In III, IV, V, VI, VII and IX, C-HÁ Á ÁO hydrogen bonds also contribute to the cohesion of the crystal structure.   Table 2 Summary of short interatomic contacts (Å ) in the title compound.

Figure 5
The

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. All C-bound H atoms were placed at calculated positions and refined using a riding model, with C-H = 0.95-1.00 Å , and with U iso (H) = 1.2 or 1.5U eq (C). The O-bound H atoms were located in a difference-Fourier map and were freely refined.    (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2020).

2,2′-[(3,5-Di-tert-butyl-4-hydroxyphenyl)methanediyl]bis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one)
Crystal data Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.